Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
  • B60K6/00—Arrangement or mounting of plural diverse prime-movers for mutual or common propulsion, e.g. hybrid propulsion systems comprising electric motors and internal combustion engines ; Control systems therefor, i.e. systems controlling two or more prime movers, or controlling one of these prime movers and any of the transmission, drive or drive units Informative references: mechanical gearings with secondary electric drive F16H3/72; arrangements for handling mechanical energy structurally associated with the dynamo-electric machine H02K7/00; machines comprising structurally interrelated motor and generator parts H02K51/00; dynamo-electric machines not otherwise provided for in H02K see H02K99/00
  • B60K6/08—Prime-movers comprising combustion engines and mechanical or fluid energy storing means
  • B60K6/12—Prime-movers comprising combustion engines and mechanical or fluid energy storing means by means of a chargeable fluidic accumulator
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
  • B60K6/00—Arrangement or mounting of plural diverse prime-movers for mutual or common propulsion, e.g. hybrid propulsion systems comprising electric motors and internal combustion engines ; Control systems therefor, i.e. systems controlling two or more prime movers, or controlling one of these prime movers and any of the transmission, drive or drive units Informative references: mechanical gearings with secondary electric drive F16H3/72; arrangements for handling mechanical energy structurally associated with the dynamo-electric machine H02K7/00; machines comprising structurally interrelated motor and generator parts H02K51/00; dynamo-electric machines not otherwise provided for in H02K see H02K99/00
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
  • F04B49/16—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00 by adjusting the capacity of dead spaces of working chambers
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B1/00—Engines characterised by fuel-air mixture compression
  • F02B1/02—Engines characterised by fuel-air mixture compression with positive ignition
  • F02B1/04—Engines characterised by fuel-air mixture compression with positive ignition with fuel-air mixture admission into cylinder
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B75/00—Other engines
  • F02B75/02—Engines characterised by their cycles, e.g. six-stroke
  • F02B2075/022—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle
  • F02B2075/025—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle two
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/60—Other road transportation technologies with climate change mitigation effect
  • Y02T10/62—Hybrid vehicles

Definitions

• the invention relates to a powertrain in particular for a motor vehicle and relates more particularly to such a group equipped with a hydrostatic transmission device.
• a conventional hydrostatic transmission device generally comprises at least one pump delivering a liquid, most often oil in a volumetric hydraulic motor.
• the pump piston can be actuated by a heat engine, usually an internal combustion engine.
• regulation means are provided to adapt the flow rate of one of the two sub-assemblies when that of the other varies. This is done by changing its volumetric capacity, generally by varying the useful stroke.
• the invention relates essentially to a powertrain combining an internal combustion engine, and a particular hydrostatic transmission device.
• the invention therefore relates to a powertrain, in particular for a motor vehicle, comprising an internal combustion engine, characterized in that said engine is mechanically coupled to a hydrostatic transmission device, comprising at least one piston pump driven by said internal combustion engine and a positive displacement motor connected to be powered by said pump, in that said compression chamber of the pump in which said piston moves contains or is in permanent communication with an elastic accumulator, and in that the latter comprises or is associated with means for adjusting its elasticity.
• This elastic accumulator can very advantageously be arranged in the extension of the bore of the piston of the pump, that is to say in the pump body itself.
• this accumulator can use the elasticity of a gas trapped in a variable volume enclosure. It can also include a block of elastomeric material. It is also possible to use the "elasticity" of a mobile assembly subjected to a magnetic field tending to stabilize it in a given position and thus to exploit a certain elastic return force generated magnetically on said mobile assembly each time it is moved away from its stable position. Finally, for simple applications, it is also possible to envisage using a simple mechanical spring arrangement bearing on a movable wall of the compression chamber of the pump. For the majority of embodiments, the invention provides the possibility of also modifying the stiffness of the elastic accumulator. More precisely, for a given machine, the ranges of variation of the stiffness and of the elastic calibration will be predetermined by structural characteristics.
• the invention also relates to a motor vehicle incorporating this type of powertrain.
• FIG. 1 schematically shows a hydrostatic transmission device with pneumatic elastic reaction
• Figure 2 is a schematic representation similar to Figure 1 of another embodiment of hydrostatic transmission device with pneumatic reaction;
• FIG. 3 is a schematic representation similar to Figure 1, of another embodiment of hydrostatic transmission device with pneumatic reaction;
• FIG 4 is a schematic representation of another embodiment using an elastic reaction by elastomer block;
• FIG. 5 is a schematic representation of another embodiment using an elastic reaction of the magnetic type
• FIG. 6 is a general schematic view of a powertrain according to the invention and comprising in particular a hydrostatic transmission device of the kind shown in Figure 1;
• - Figure 7 is a schematic transverse representation of the same powertrain, seen at the crankshaft of the internal combustion engine, according to the section VU-VU of Figure 5;
• FIG. 8 is a detail view illustrating the shape of the scanning lights of the internal combustion engine of Figures 6 and 7;
• - Figure 9 is a schematic detail view showing a possible embodiment of a scanning pump, delivering compressed air for scanning the cylinders of the two-stroke engine of Figures 6 and 7;
• - Figure 10 is a schematic detail view showing a possible embodiment of an oscillating starter-generator;
• FIG. 11 is a schematic view of a control system for varying both the elasticity of the elastic accumulator and the amount of fuel introduced into the internal combustion engine;
• FIGS. 12a to 12c are diagrams showing several possible locations of the powertrain according to the invention on a motor vehicle;
• - Figure 13 describes a pneumatically controlled variant of said elastic accumulator
• - Figures 14a, 14b are detailed views illustrating a variant for eliminating the scanning pump of Figures 7 and 9;
• the hydrostatic transmission device 11 essentially comprises a pump 12 with piston 13 and a volumetric motor 14 inserted in a hydraulic circuit 15 shown diagrammatically in broken lines, to be supplied by the pump.
• the fluid circulating in this circuit is generally oil.
• the pump comprises a compression chamber 16 provided with a suction valve 17 and a discharge valve 18.
• the motor 14 is connected downstream from the discharge valve 18.
• the piston 13, movable in a bore 19 opening into the compression chamber 16, is driven in an alternating back-and-forth movement by means not shown in FIG. 1.
• this is, of course, a heat engine, and more particularly an internal combustion engine.
• the volumetric hydraulic motor 14 is of conventional design but it is of simpler and more robust structure because, in the context of the invention, it can be, and preferably, is of constant displacement.
• the compression chamber 16 of the pump contains or is in permanent communication with an elastic accumulator 20.
• “permanent communication” it is meant that said communication does not depend on the opening or closing state of any valve, the elastic accumulator reacting directly on the pressure prevailing in the compression chamber 16.
• the elastic accumulator 20 is coupled to a first movable wall 22 belonging to the compression chamber of the pump, that is to say - say forming a wall of this room.
• this wall 22 is constituted by a free piston moving in a bore 23 made in the pump body, coaxial with the bore 19. This piston is urged towards a shoulder 24 by said elastic accumulator 20.
• the latter comprises a chamber 26 filled with a gas and also arranged in the pump body, coaxial with the pistons 13 and 22.
• This chamber is defined in a bore 28 of larger diameter than that of the bore 23 and it is limited axially, on the one hand by the piston 22 and on the other hand, by a second movable wall 32, in the shape free piston, slidably mounted in the bore 28.
• a groove 48 In the bore 23 is provided a groove 48 only discovered when the piston 22 is in abutment against the shoulder 24. In this way, this groove 48 is closed from the start of '' displacement of the piston 22, at each stroke and the gas contained in the chamber 26 is thus immediately isolated.
• the charge of nitrogen in chamber 26 can thus be "updated” with each cycle which causes displacement of the piston 22.
• the charge of each room 26 is therefore strictly the same.
• This groove opens a bore 34 provided with a non-return valve 36 by which the mass of gas can be supplemented over time, from an external source not shown, to compensate for leaks.
• the bore 34 is in communication with the control device via the channel 35 (see figure 11 below).
• the gas under pressure in the chamber urges the piston 32 towards a shoulder 38.
• the elastic accumulator 20 comprises or is associated with means for adjusting its own elasticity. In the example shown, it is a variable volume chamber, 42, adjustable, filled with an incompressible fluid, normally oil. This chamber is separated from the elastic accumulator by said second movable wall 32.
• this variable volume chamber 42 is arranged between the deformable part of the elastic accumulator, that is to say the chamber 26 and the wall fixed end 30 constituted for example by a plug provided with annular seals closing the bore 28.
• Control means 44 are provided for adjusting the quantity of incompressible fluid in the chamber 42.
• the fluid is distributed by a control slide 46, the outlet of which communicates by a conduit 47 pierced in the upper part of the bore 28 in the vicinity of the extreme position of the piston 32 for which this piston is in abutment against the shoulder 38.
• the operation of the hydrostatic transmission device which has just been described is as follows.
• the fluid injected into the chamber 42 is the parameter on which one acts to adjust the elasticity adjustment means of the elastic accumulator 20. It is clear that, the more the volume of the chamber 42 increases, the more the setting pressure of the gas trapped in chamber 26 is high.
• This setting pressure can be defined as being the pressure exerted on the piston 22 by the elastic accumulator, that is to say by the chamber 42 filled with incompressible fluid.
• the torque increases when the speed of the motor decreases, which constitutes a very advantageous operating characteristic for many applications, in particular automobile traction.
• the torque will automatically increase at the slightest deceleration of the vehicle, for example if it approaches a slope.
• a torque law inversely proportional to the speed of the hydraulic motor, for a "notch" of given fuel supplied to the motor actuating the pump piston.
• variable volume chamber In the variant of FIG. 2, the similar structural elements bear the same numerical references and will not all be described again in detail.
• This embodiment also uses an elastic gas capacity. It differs from the previous one by the location of the variable volume chamber. Indeed, the chambers 26 and 42 are reversed, the variable volume chamber being limited axially by the pistons 22 and 32. In other words, said variable volume chamber 42 is arranged between the deformable part of the elastic accumulator 20 (c ' that is to say the chamber 26) and the compression chamber of the pump.
• the chamber 26 filled with gas is defined in the immediate vicinity of the compression chamber 16 of the pump.
• said first movable wall 22a is common to chambers 16 and 26.
• said first movable wall 22a. is a deformable membrane.
• Said second movable wall 32a separating the chamber 26 filled with gas from the variable-volume chamber 42 is also constituted by a membrane of the same kind, arranged parallel to said first wall 22a. Consequently, in this embodiment, the deformable part the elastic accumulator is also placed between the compression chamber 16 of the pump and the variable volume chamber 42 filled with liquid.
• the control means 44 are similar to those of FIG.
• said elastic accumulator essentially consists of a block of elastomeric material 26b comprising two parallel end surfaces, respectively in contact with said first and second movable walls 22b and 32b here being in the form of free pistons adapted to move in the same bore 49.
• the block of material elastomer 26b is therefore compressed uniaxially between the two pistons. Elastomeric materials with low hysteresis are currently found suitable for this use.
• the general arrangement of the elements of this variant is comparable to that of FIGS.
• the deformable part of said elastic accumulator being located between the compression chamber 16 of the pump and said variable volume chamber 42.
• the block 26b has a wall lateral concave profile leaving an annular space 50 in the bore to allow free deformation of the elastomer block.
• a purge duct 51 communicates with this annular space.
• FIG. 5 comprises an elastic accumulator implementing return forces of magnetic origin.
• Said first movable wall 22ç_ closing the compression chamber is constituted by a movable free piston in a bore 23c located in the extension of the piston 13 and coaxially therewith.
• the free piston is made of ferromagnetic material while the bore 23c is made in a block of insulating material, such as resin.
• An annular groove 53 is formed in the bore 23c and houses a magnetic frame 54, in this case one or a set of coils. The magnetic field generated is such that it tends to place the piston 22c in a predetermined position, as illustrated in FIG. 5.
• the means for adjusting the elasticity are therefore means for adjusting the current in one or a set of electromagnets.
• FIGS. 6 and 7. This group consists of an internal combustion engine 60 comprising at least one combustion chamber 61 in which a piston 62 operates and at least one hydrostatic transmission 11, of the type described above and whose piston 13 is mechanically coupled to the piston 62 of the internal combustion engine, to be driven by it.
• the hydrostatic transmission device conforms to that of FIG. 1 and this part of the group will not be described again in detail.
• the or each pump 12 is inserted into a hydraulic circuit 15a to discharge the oil into a volumetric hydraulic motor 14 and that the compression chamber 16 in which the pump piston moves contains or is in permanent communication with a elastic accumulator 20.
• the powertrain comprises four pumps 12 and in this example, the positive displacement motor 14 is common to these four pumps.
• the internal combustion engine 60 is here a two-stroke, scanning engine. This is a diesel engine but a petrol engine version is perfectly possible.
• This engine 60 comprises at least one assembly 65 comprising a cylinder 63 and a piston 62 delimiting the combustion chamber 61.
• the piston is free travel, that is to say that it is not coupled to any crankshaft.
• the engine includes generally two such sets 65 cylinder and piston, arranged parallel as shown in Figure 6 and preferably four sets arranged parallel to each other, in a barrel configuration, as clearly shown in Figure 7. More specifically, two such sets 65a., 65b or 65c, 65d are coupled, on the one hand to a reversing mechanism 67A or 67B and on the other hand to respective pumps 12a, 12b.
• the pair of assemblies 65a, 65b is coupled by its pistons to the reversing mechanism 67A while the pair of assemblies 65c, 65d is coupled to the reversing mechanism 67B.
• the two pairs of sets operate in phase opposition, so that the set is dynamically balanced.
• the aforementioned reversing mechanism 67 comprises a reversing lever 70 mounted pivoting in its middle around a rotary shaft 71A or 71B, respectively. This shaft is perpendicular to the two free stroke pistons 62 to which it is coupled.
• Each lever 70 thus comprises two equal branches 74a, 74b or 74c, 74d, respectively, extending on either side of its median pivot point, that is to say of the pivot axis of the corresponding tree 71.
• the free stroke piston (s) 62a-62d are respectively connected, in an articulated manner, to the ends of the branches 74a-74d, by means of links 76a-76d, respectively articulated between said ends of said branches and the pistons 62.
• the piston 13 of each pump 12a-12d is mechanically coupled to a corresponding branch 74a-74d of one of the reversing levers. This articulated connection is made via links 78a, -78d or equivalent mechanisms.
• Each link 78a-78d is articulated at an intermediate point 79a-79d of the corresponding lever branch.
• the distance between this point of articulation and the pivot axis of the shaft 71A or 71B is chosen as a function of the respective speed ranges of the internal combustion engine and of the pump or pumps 12 of said hydrostatic transmission device 11.
• balancing means also constituting means for synchronizing said assemblies, are provided to maintain the operation of the two pairs of assemblies 65a, 65b and 65ç_, 65d phase shifted by 180 ° and thus allow dynamic balancing of the motor. and the hydrostatic transmission device.
• These synchronization means are here mechanical.
• the pivot shafts 71A and 71B, coaxial and situated in the extension of one another (FIG. 7) are linked to a mechanism of planet and planetary gears, forming the main part of said synchronization means.
• Each shaft 71A, 71B secured to the corresponding reversing lever is linked to a satellite pinion 80A, 80B, meshing with a single planetary pinion 82 whose axis of rotation coincides with the axis of symmetry of the barrel arrangement of the cylinder assemblies and free stroke piston 65a-65d. More precisely, each satellite pinion 80A, 80B, is fixed to the internal end of the corresponding shaft 71A, 71B, while the planetary pinion 82 is fixed to the end of a shaft 83 mounted rotating about itself around of said axis of symmetry.
• This shaft extends parallel to the four cylinders and comprises, towards its opposite end, a set of cams (not visible in the drawings) controlling the operating cycles of the different cylinders of the engine.
• this camshaft 83 drives fuel injection pumps 85, oil pumps 86 and a combustion regulator 87 which will be described later.
• the injection pumps 85 respectively supply so-called “storage” injectors 88, whose principle is known.
• the oil pumps 86 supply cylinders 90 respectively controlling the exhaust valves 92 of the engine.
• This type of hydraulic control is known and makes it possible to vary the duration and the phase of the hydraulic pulse controlling each exhaust valve. We can therefore advance or delay the opening or closing of each of these valves, as required.
• This ability linked to that of being able to vary at will the compression and expansion ratios of the internal combustion engine (because this engine has free stroke pistons) makes it possible to adapt this engine to all the requirements of diesel combustion.
• the fuel injection which is done after closing the exhaust valves is carried out by conventional injectors and pumps, the cylinder head being further provided with a spark plug. for each cylinder.
• the internal combustion engine is preferably a two-stroke scanning engine. It therefore comprises a sweeping air reservoir 94, generally cylindrical, surrounding the cylinders 63. This reservoir supplies compressed air to the combustion chambers of the different cylinders, through ports 93 made in the different cylinders.
• the lights of a cylinder are discovered by the piston during each scanning phase. Each light has the shape illustrated in FIG. 8. At the level of the combustion chamber 61, the orifice of said light has two parallel longitudinal edges extending along the generatrices of the internal surface of the cylinder.
• the orifice of the light has two curved longitudinal edges. These extend substantially parallel to those of the internal orifice on the side of the farthest end of the exhaust valves and they gradually "tilt" to the opposite end, while remaining parallel to each other. L f "tilt" extends over a total angular sector of 30 °.
• the air is introduced into the reservoir 94 by a swinging air pump 96, oscillating, and / or by a conventional supercharging system comprising a turbine 97 connected to an exhaust manifold (not shown) and mechanically coupled to a compressor. 98.
• the compressed air outlet of the compressor is connected to the inlet 99 of the pump 96 (FIG. 7) by means of an air cooler of known type, not shown.
• the outlet 100 of this pump communicates with said purge air tank 94.
• the pump 96 which in this case constitutes a second compression stage, is a rotor assembly 95 with a double vane, this rotor being mounted at the end of one of the shafts (in this case the shaft 71A) d 'A reversing lever 70.
• the pump 96 is divided into several compartments communicating with each other by suction valves 101 and discharge valves 102.
• the inlet 99 communicates with two compartments d suction 103, symmetrical with respect to the axis of rotation of the rotor and the outlet 100 communicates with two discharge compartments 104, also symmetrical with respect to this axis.
• These four compartments are inscribed between radial walls which carry all of the valves 101 and 102.
• the rotor 95 operates in two compression chambers 105, symmetrical with respect to the axis.
• the rotor divides these compression chambers into four volumetric capacities of variable volumes.
• the rotors driven by the shaft 71A describe an oscillating movement in the compression chambers 105.
• the operation of the pump is evident from the description which appears above.
• the pump is especially effective at start-up or at idle. It is nevertheless sufficient for a vehicle with small displacement and medium performance. However, for better performance, and especially for heavy vehicles, it is generally preferable to cascade the supercharging compressor and the pump. In this case, we can consider another air cooler downstream of the pump. The purge air supply is thus better ensured at all speeds and starting is easier.
• FIG. 9 is also equipped with an electric starter 108 with oscillating reciprocating movement, shown in FIG. 9.
• the rotor of this device is coupled to the shaft of one of the aforementioned reversing levers, at 1 'occurrence here 1 * shaft 71B so that the pump and the starter are arranged coaxially and on either side of the engine block. After starting, the device is switched to operate as a generator.
• the rotor 109 is fixed to the end of the shaft 71B and driven by it.
• This starter operates on the principle known as "variable reluctance".
• the rotor 109 made of laminated sheet metal, has six poles 110 regularly distributed circularly and the stator, also with laminated structure comprises eight poles 111 also regularly distributed circularly, each of the poles of the stator carrying a coil 112.
• the number of rotor and stator poles may be different.
• a version with twelve poles for the rotor and sixteen poles for the stator even has superior performance (higher torque and lower magnetic losses) all other things being equal.
• an oil circulation circuit 122 is established between an inlet and an outlet of the circuit cooling cylinders. It successively comprises a cooling radiator 124 and a circulation pump 125.
• the main circuit 15a defined between the pumps 12 and the motor 14 comprises (from a pump outlet manifold) a safety valve 126, the engine 14, a safety valve 127, an isolation valve 128, the cooling device 124 and a booster pump 130 (separate from the pump 125) delivering oil to the inlet valves of the pumps 12.
• the cooling flow is therefore independent of the flow of the hydrostatic transmission device.
• the safety valve 126 is calibrated to maintain the pressure below a selected maximum value.
• the safety valve 127 connected to the low pressure outlet of the hydraulic motor 14, maintains the pressure below a chosen maximum value (for a motor vehicle) for the adhesion of the wheels to the ground, when the progressive slide valve isolation 128 closes when braking or stopping.
• FIG. 11 describes a regulation system of the power unit, remarkable for its simplicity. This regulation system is well suited to a motor vehicle. It breaks down into a so-called “slow” sub-assembly 139 connected to the accelerator pedal 140 and into a so-called “fast” sub-assembly, constituted by the combustion regulator 87 mentioned above.
• the accelerator pedal 140 is mechanically coupled to at least one slide 46 described with reference to FIG. 1 and which makes it possible to adjust the pressure in the chambers 26 of the elastic accumulators.
• the channel 35 described above is connected to a bore 142 within which a correction piston 143 coupled to the accelerator pedal r 140. This piston acts against a calibrated spring 145.
• the combustion regulator 87 comprises a hollow piston 160 filled with oil and whose internal cavity 161 houses a counterweight 159. This piston 160 is movable in a bore coaxial with the camshaft 83 and located in the extension thereof.
• the piston 160 is biased towards the camshaft by a spring 163 bearing against a shoulder of said piston.
• the camshaft has at its end a cylindrical cam 164 coupled by form connections (with ramps) to the piston 160.
• the coupling is such that the oscillating rotary movement of the camshaft communicates to the piston 160 a linear movement oscillating representative of that of the pistons 62 of the internal combustion engine.
• the piston 160 is therefore subjected to accelerations and decelerations proportional to those of the engine pistons. These accelerations and decelerations are therefore a measure of the combustion pressure.
• the internal cavity 161 of the piston 160 can be placed in communication, by a lateral orifice 162 with an oil supply groove 165, when the spring 163 is relaxed.
• the same cavity 161 can communicate through the orifice 162 with the bore 168 of a control drawer 169 comprising two shoulders respectively controlling the opening or closing of two grooves 170 and 171 made in the bore 168.
• the groove 171, which cooperates with the other shoulder of the drawer, is connected to a hydraulic cover.
• a spring 174 bears against the other end of the drawer 169. This spring therefore urges said drawer in a direction tending to uncover the groove 170.
• the spring is located in a cavity 176 receiving oil or air under pressure, the pressure of this oil or of this air is representative of the boost pressure of the engine internal combustion.
• the middle part of 1 • bore 168, between the two shoulders, that is to say the hydraulic outlet of the slide, is connected to the chamber of a jack 180.
• the piston of this jack is coupled to a control mechanism 181 fuel injection pumps.
• An orifice 182 ensures complete emptying of the cavity 183 to avoid a discharge of the counterweight 159 into the piston 160.
• the operation is as follows: It is assumed that the driver wishes to increase the speed of his vehicle. A stress on the accelerator pedal 140 therefore results in a "hardening" of the elastic accumulators 20 associated with the various pumps. Consequently, the flow accumulated in the elastic accumulators is lower and the flow in the hydraulic motor increases.
• the elastic accumulators restore less energy and the compression of the engine tends to decrease during the following cycles, since it is a piston engine with free strokes. Energy must therefore be reintroduced into the system by increasing the amount of fuel injected. This is what regulator 87 automatically achieves.
• the acceleration of the camshaft 83 is proportional to the acceleration of the pistons of the internal combustion engine. Consequently, the piston 160 behaves like the pistons 62 of the internal combustion engine, with the same variations in acceleration.
• the flyweight 159 on the contrary, by its inertia, tends to remain stationary inside the piston 160. This flyweight therefore transmits to the oil, which is trapped in the cavity 161, pressure variations representative of those of the pistons of the internal combustion engine. These pressure variations act on the position of the slide 169 which controls the flow rate of the fuel injection pumps.
• the pressure setpoint applied to the slide valve by means of the calibration of the spring 174, also takes account of the boost pressure.
• FIG. 12a the powertrain is typically that which has just been described, that is to say comprising an internal combustion engine 60 with four cylinders, driving four pumps. These pumps supply a single hydraulic motor 14, which mechanically drives a differential D coupled to the front or rear wheels. The four hydraulic pumps 12 therefore supply the hydraulic motor 14 in parallel. This gives a very compact assembly for front or rear traction.
• the four pumps are divided into groups of two pumps 180 ° out of phase with each other a and b on the one hand, ç and d on the other.
• Each group of pumps supplies a hydraulic motor 14a or 14b.
• the motor 14a is coupled to the front wheels via a differential Da and the motor 14b is coupled to the rear wheels via a differential Db.
• the motor can be either front, rear or in the central position as shown. FIG.
• each pump 12c describes another embodiment in which each pump 12 supplies separately a hydraulic motor 114, of a known type, combined with each wheel.
• the differential effect between the front wheels on the one hand, and the rear wheels on the other hand, is obtained by hydraulic communications between the front pumps on the one hand and the rear pumps on the other hand.
• These communications Ca., Cb are either limited constant opening, or proportional opening controlled by the direction of the vehicle.
• FIG. 13 represents a variant in which the control of the elastic accumulator is simpler and faster.
• the variable-volume chamber 42 of FIGS. 1 to 3 is omitted because one acts directly on the loading of gas in the chamber 26 defining said accumulator.
• only one pump 12 has been shown coupled to its elastic accumulator.
• the stiffness of the latter is controlled by a hydropneumatic control system 239 intended to replace the sub-assembly 139 of FIG. 11.
• the control system 239 is therefore coupled to an accelerator pedal and controls several elastic accumulators, in parallel, for example four chambers 26 in the case where the engine is equipped with four mobile assemblies
• Each chamber 26 is connected to a charge valve 240 by a non-return charge valve 242 and to a discharge valve 244, by a discharge non-return valve 246.
• the two valves 240, 241 are biased towards their seats by respective springs 248, 249.
• the conduits connecting the valves 242 to the valve 240 open into a chamber 243 enclosing the spring 248.
• the conduits connecting the valves 246 to the valve 244 open into a chamber 245 containing the spring 249.
• valve seat 240 On the other side of the valve seat 240, with respect to the spring, there is defined an annular chamber 250 traversed by the valve stem 252 connected to a piston 258 moving in a bore 262. Similarly , on the other side of the valve seat 244, relative to the corresponding spring, is defined an annular chamber 254 traversed by the valve stem 256 connected to a piston 260 moving in a bore 264.
• the two chambers 250 and 254 are in direct communication with a 255 pressurized gas tank, here nitrogen brought to 120 bars.
• the springs 248, 249 have sufficient force to overcome the force developed on the valves by the pressurized gas and to keep said valves closed when the system is not stressed. Under these conditions, the quantity of gas trapped in the or each elastic accumulator remains constant.
• the two pistons 258, 260 are actuated by a pressurized hydraulic fluid admitted into respective chambers of the bores 262, 264, to cause the opening of the corresponding valves.
• the two bores 262, 264 are therefore respectively connected to two grooves 265, 266 of a distributor 263 with drawer 267.
• the two grooves 265, 266 are closed in a variable manner by respective control surfaces 268, 269 of the drawer, delimiting a high pressure chamber 270 connected to a high pressure hydraulic source and located between the two grooves 265, 266.
• Unloading chambers 272, 274, connected to a hydraulic tank, are respectively defined between the control surfaces 268, 269 of the drawer and end surfaces 276, 278, respectively, of this same drawer.
• the latter is held in the rest position by opposing springs 279, 280.
• the end bearing 278 evolves in a chamber 282 connected to a hydraulic transmitter coupled to the accelerator pedal, not shown. This chamber therefore receives a control pressure determined by the user.
• the end bearing 276 is extended by a piston 283 of smaller section, receiving at its end the pressure which prevails in the chamber 245 (conduit 284) between the valves and the valve.
• This pressure is therefore representative of the minimum pressure prevailing in the elastic accumulators associated with the pumps, that is to say the pressure when the pump piston is at its suction neutral point.
• the supply of the chambers 26 of the elastic accumulators is controlled by the slide 263 which controls the two valves 240, 244.
• the control oil admitted into the chamber 270 is taken upstream of the hydraulic motor 14.
• the slide 267 moves according to the values of the pressures applied on the one hand, in the chamber 282 under the action of the operator and, on the other hand, on the end of the piston 283.
• the operator wants to increase the power he actuates the accelerator and the oil pressure in chamber 282 becomes predominant.
• the drawer moves in a direction controlling the opening of the valve 240 and the closing of the valve 244.
• the non-return charge valves 242 open, which makes it possible to charge the elastic accumulators from a given point cycle of the corresponding pumps, until a new equilibrium is reached.
• valve 240 remains closed.
• the elastic accumulators 24 are then charged at a new pressure. If the operator wants to reduce the power, he commands a drop in pressure in the chamber 282, which results in a displacement of the slide 267 in the other direction.
• the valve 244 opens and the valve 220 closes.
• the discharge check valves 246 open from a given point in the corresponding pump cycles, to discharge the elastic accumulators until a new one balance is established.
• the regulation is very fast because it takes about five cycles to fully charge or discharge the elastic accumulators. This only represents a delay of approximately 0.15 seconds. As the delay in regulating the "notch" of fuel, described with reference to FIG. 11, is of the same order of magnitude, it is possible to envisage taking maximum torque in a delay of 0.3 seconds.
• the starting motor 108 with reciprocating movement, allows on the one hand, to actuate the pistons of the internal combustion engine at start and on the other hand, drive the sweep pump 96, reciprocating, especially useful for starting and idling.
• the improvements shown in FIGS. 14 and 15 make it possible to eliminate the sweeping pump (by entrusting this role entirely to the compressor 98) as well as the starting motor 108.
• a hydraulic turbine 300 (FIGS. 14a, 14b) is directly coupled to the shaft 301 which drives the compressor 98, that is to say more precisely the shaft connecting the turbine 97 and said compressor.
• This shaft 301 is mounted in a bore of a frame or support 302 inside which is defined a cavity 303 housing the rotor 304 of the turbine, which is mounted and fixed on the shaft 301.
• a nozzle 305 opening into said cavity is oriented towards the blades of this rotor.
• the nozzle 305 is supplied with hydraulic fluid by a pump 306 (see FIG. 15), for example of the gear pump type, via a non-return valve 307.
• the pump is driven in rotation by a conventional electric motor 308, c 'is to say continuous rotation and not reciprocating, as above. This solves the problem of supplying air to the sweeping chamber 94, at any speed, as well as at start-up, by driving the only compressor 98.
• This starter 310 comprises a housing 312 in which is engaged one end of the oscillating rotary shaft 71B (for example) of the reversing mechanism visible in FIGS. 6 and 7.
• the housing 312 defines a cavity provided with cylindrical walls and radial walls, inside which a rotor 314 with two opposite vanes 315 evolves.
• This rotor is mounted on the shaft 71B and integral in rotation with the latter, by grooves.
• Said rotor 314 has a cylindrical hub 316 coaxial with the shaft 71B and rotatably mounted between two cylindrical bearing surfaces of small diameter of said cavity.
• Said rotor 314 is moreover in contact, by the opposite ends of its pallets, with cylindrical bearings of large diameter of the same cavity, so that they divide this cavity into four chambers 318a, 318b and 319a, 319b symmetrical two to two with respect to the axis of rotation of the shaft 71B.
• Conduits 320a ,, 320b interconnected with one another open respectively into the two chambers 318a, 318b on radial walls of the cavity.
• the two chambers 318a, 318b_ are therefore in permanent communication.
• the two chambers 319a, 319b are therefore in permanent communication.
• the angular movement of the double pallet inside the cavity is 90 °.
• the two rooms 318a, 318b communicate with a relief valve 322 urged upon opening by a spring 323. When this valve is open, it establishes communication with a hydraulic tank.
• the two chambers 319a, 319b communicate with a second relief valve 324, similar, urged upon opening by a spring 325.
• the two chambers 318a, 318b are further connected to the pump 306 via a first drawer 310 evolving in a bore 312.
• This drawer is designed to take two predetermined positions (establishing or interrupting communication between said pump and the chambers 318) by means of an arrangement of two ball grooves 313.
• One end of this drawer is placed in look of an actuating member 314 such as a push button or the like. An action on the latter causes the drawer to move in a direction tending to establish communication between the pump 306 and the two chambers 318a, 318b.
• the other two chambers 319a, 319b are connected (via the conduits 321a, 321b) to a hydraulic accumulator 326 fixed to the housing. The connection between said conduits and said accumulator is not visible in the drawings.
• chambers 319a, 319b are also connected to the "outlet" of said first drawer by a hydraulic circuit comprising a non-return valve.
• a second drawer 332 moving inside a bore 333.
• This second drawer is urged to "close” by a spring 334 bearing at one of its ends.
• the other end of the slide 332 evolves in a part of the bore 333 in communication with a conduit 334.
• the latter is capable of being placed in communication with one or the other of the pairs of chambers 318, 319, via respective grooves 335, 336 formed in the hub 316 of the rotor 314.
• the end of the slide 310 which is opposite to that which cooperates with the actuating element d 1 314, operates in a portion of the bore 312 in communication with the outlet of the valve 330 non-return.
• the operation is as follows.
• the pump 306 is driven by its electric motor and sends pressurized oil to the drawer 310.
• the drawer 310 is moved and the oil under pressure, flowing around of valve 322, pushes it back against its seat.
• the oil then enters the two chambers 318, which causes the rotor and the shaft 71B to rotate until the groove 336, having made approximately a quarter turn, enters the chamber 318b.
• the oil under pressure then pushes the drawer 332 back into the open position. From this moment, the oil passes through the non-return valve 330, crosses the slide 332 and closes the valve 323.
• the pressure builds up in the chambers 319 and compresses the accumulator 326.
• the pressure in the chambers 319 always remains lower than that prevailing in the chambers 318 due to the calibration of the non-return valve 330.
• the rotor 314 therefore remains in place until the pressure increasing in the bore 312, pushes the slide 310 causing the valve 322 to open. The latter then releases a large leakage section which discharges the chambers 318 without flow resistance.
• the rotor 314 therefore rotates in the opposite direction under the effect of the accumulator 326.
• the engine starts.
• the groove 335 then establishes communication with the conduit 334, which allows the drawer 332 to return to its original position, under the effect of the spring 339. All the elements are therefore in their position from the start of the start cycle. In the event of a poor start of the internal combustion engine, it is therefore possible again to press the actuating member 314 and cause a new launch cycle.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Transportation (AREA)
• General Engineering & Computer Science (AREA)
• Arrangement Or Mounting Of Propulsion Units For Vehicles (AREA)
• Control Of Fluid Gearings (AREA)
• Reciprocating Pumps (AREA)
• Supercharger (AREA)
• Fluid-Pressure Circuits (AREA)
• Output Control And Ontrol Of Special Type Engine (AREA)

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Applications Claiming Priority (2)

Publications (2)

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ID=9364648

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• 1988
  • 1988-03-25 FR FR8803946A patent/FR2629171B1/fr not_active Expired - Fee Related
• 1989
  • 1989-03-24 KR KR1019890701974A patent/KR900700314A/ko not_active Application Discontinuation
  • 1989-03-24 JP JP1504137A patent/JPH03503394A/ja active Pending
  • 1989-03-24 EP EP89904086A patent/EP0407436B1/de not_active Expired - Lifetime
  • 1989-03-24 AU AU34127/89A patent/AU626544B2/en not_active Ceased
  • 1989-03-24 WO PCT/FR1989/000141 patent/WO1989009144A1/fr active IP Right Grant
  • 1989-03-24 US US07/566,353 patent/US5167292A/en not_active Expired - Fee Related
  • 1989-03-28 CA CA000594909A patent/CA1325578C/fr not_active Expired - Fee Related

Non-Patent Citations (1)

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